Problem: Khan.scratchpad.disable(); Daniel sells magazine subscriptions and earns $$4$ for every new subscriber he signs up. Daniel also earns a $$38$ weekly bonus regardless of how many magazine subscriptions he sells. If Daniel wants to earn at least $$91$ this week, what is the minimum number of subscriptions he needs to sell?
Explanation: To solve this, let's set up an expression to show how much money Daniel will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Daniel wants to make at least $$91$ this week, we can turn this into an inequality. Amount earned this week $\geq $91$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $91$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $4 + $38 \geq $91$ $ x \cdot $4 \geq $91 - $38 $ $ x \cdot $4 \geq $53 $ $x \geq \dfrac{53}{4} \approx 13.25$ Since Daniel cannot sell parts of subscriptions, we round $13.25$ up to $14$ Daniel must sell at least 14 subscriptions this week.